Telephone system.



. H. P. GLAUSEN.

TELEPHONE SYSTEM.

APPLICATION FILED MAEJI, 1903.

COLUMBIA PLANOGRAPH C0., WASHINGTON, D. C.

Patented Nov. 5, 1912.

rinrran s'ra'rns Parana orrroa.

HENRY P. CLAUSEN, OF CHICAGO, ILLINOIS, ASSIG-NOR, BY MESNE ASSIGNMENTS, TO STROMBERG-CARLSON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

To all whom it may concern:

Be it known that I, HENRY P. CLAUSEN, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Telephone Systems, of which the following is a specification.

My invention relates to that type of telephone system in which all of the current, both for talking and signaling purposes is supplied from suitable sources located at the exchange or central station.

Generally stated, the object of my invention is the provision of an improved and highly efficient telephone system of the common battery or central energy type.

A special object is to provide an improved arrangement and mode of operation of the supervisory and line signals.

Another object is to provide an improved construction and arrangement of the circuits and impedance coils through Wl11Cl1 the current is supplied to the subscribers lines.

It is also an object to provide certain details and features of improvement tending to increase the general efficiency and serviceability of a telephone system of this particular character.

To the foregoing and other useful ends my invention consists in the matters hereinafter set forth and claimed.

The accompanying drawing is a diagram illustrating a subscribers line and telephone set, and showing also the construction and arrangement of the line signal apparatus, and also the construction and arrangement of one of the operators cordcircuits. As thus illustrated, my invention may comprise a subscribers telephone set A, of any suitable known or approved construction. This telephone set may have complete metallic line connection with the answering jack B and the multiple jack C on the switchboard at the exchange or central station. It will be understood that any number of multiple jacks can be connected with the line leading from the answering jack 7 on the switchboard.

The operators cord-circuit D may constitute a portion of the apparatus of the switchboard upon which the subscribers line terminates, and is preferably provided at its ends with plugs d, d. These plugs can Specification of Letters Patent.

Application filed March 11, 1903.

Patented Nov. 55,1912.

Serial No. 147,323.

be of the usual and well known tion, each one being adapted for insertion in a spring-jack connected with the subscribers line, and each one being provided with tip and sleeve contacts. -With this arrangement the cord-circuit is of the twoway type.

For convenience in illustration, only one subscribers telephone set and line circuit is shown, it being understood that the balance of the subscribers telephone sets and line circuits can be of the same character as that shown in the drawing, and that any practicable number of lines may terminate at the switchboard upon which the jacks B and C and the cord-circuit D with its plugs are located. As is well understood, the said cord-circuit and plugs constitute the medium by which the operator establishes connection between any two subscribers lines, the answering plug of the cord-circuit, when the two lines are connected, being inserted in the calling subscribers jack, and the calling plug in the jack connected with the calling subscribers line. This, however, will be better understood by considering the various operations and circuit connections which necessarily take place in connecting up two subscribers.

For example, assumin that the subscriber at substation A desires to talk to another subscriber, the removal of the receiver 1 from the hook-switch 2 completes a line circuit from the battery 3 at the central station, through the connections 4, 5 and 6, through the impedance coil 7, through the line relay 8, through the limb or line conductor 9, thence through the subscribers transmitter 10, through the said hook-switch 2, through the contact point 11, through the primary 12 of the induction coil, through the conductor 13, thence through the other limb or construcline conductor 14:, through the other im pedance coil 15, and thence through the ground or common connections 16 and 17 at the central exchange or central station to said battery. The current flowing from the battery through this closed line circuit is sufficient to energize the line relay 8, thereby causing it to attract its armature 18. hen attracted, this armature closes a local cir' cuit from the battery 3, through the conductors l, 5 and 6, through the impedance coil 7, through the said armature l8 and I short-circuit the line relay of the calling its contact-point 19, thence through the con-- subscribers line. Also, the insertion of the ductor 20 and the line lamp signal 21, and calling plug into the multiple jack connected through the ground or common connections I with the called subscribers line operates to 22 and 17 to said battery. The amount of place the supervisory relay 31 in the line 70 current thus allowed to flow through this circuit, but in as much as this line circuit of closed local circuit is sufficient to cause the f the called subscribers line is still open, the

lamp 21 to rise to full glow. The operator said relay receives no current, and conseat the central station or exchange, observing quently current from the battery 3 is free to this signal, understands that the subscriber flow from the battery 3 through the super- 75 at substation A has sent in a call for connecl visor-y lamp 32, thence through the sleeve tion with some other subscribers line. Accontacts of the calling plug and the multiple cordingly, the operator then inserts the jack of the called subscribers line, and answering plug of the cord-circuit, which thence back through the ground or common may be the plug (Z in the answering-jack B, connections to said battery. This signal, as 80 which latter is connected with the calling is well known, advises the operator that the subscribers line. This act, it will be seen, called subscriber has not-answered the call. operates to short-circuit the relay 8, the tip The operator then signals the called subcontact 23 of the plug being long enough to scriber in the usual and well known manner 7 make contact with both springs 24 and 25 of until the latter answers the call. When the the jack, while the sleeve contact 26 of the called subscriber answers the call by removplug only makes contact with the testing ing the receiver from the hook-switch, the ring or thimble 27 of the jack. Thus, in line circuit is then closed, the supervisory answering the call, the line relay is autorelay 31 becomes energized, and the move- 25 matically short-circuited by the tip of the ment of the armature 33 away from its conplug, and by thus deenergizing the relay retact then opens the circuit of the lamp 32. leases its armature and opens the circuit of The obliteration of this signal advises the the line lamp signal. At such time, the curoperator that the called subscriber has rent for talking purposes is fed from one answered the call and that the two sub- 30 pole of the battery through one side of the scribers are now in communication with each line, through the impedance coil 7 and the l other. It will be readily understood that contacts 23, 24 and 25, and through the other the operators head telephone, etc, and also pole of the battery through the impedance the means for signaling the called subcoil 15. The insertion of the answering-plug scriber, can be of any suitable known or 35 in this manner also places the supervisory approved character. relay 28 in the line circuit, causing it to at-- Vith the two subscribers thus connected tract its armature 29, and thereby preventup, the talking circuit between the two subing the flow of current through the superstations includes the limbs of the two lines, visory lamp signal 30. the tip and sleeve contacts of the plugs and 40 Having thus established connect-ion with jacks, and the tip and sleeve strands of the the line, the operator then communicates cord-circuit. It will be observed that the with the subscriber in the usual well known answering end of the cord-circuit is prefermanner, and upon learning the number of ably provided with condensers X and Y, the connection desired, then proceeds to which are located in thetwotalkingstrands 5 make the proper connection. at points between the answering plug and Assuming that the subscriber at substathe springs Z of the ringing and listening tion A desires connection with a subscribers keys. In this way the talking circuit is line having a multiple jack located on the divided into two inductively connected same board on which the answering jack B halves, and the current is fed from one pole 50 is located, the operator then inserts the cal of the battery through thecord-circuit and ing plug d in said multiple jack, it being the impedance coil and jack springs and tip understood that the line circuit of the called l contacts of the plugs to one side of the cord subscriber will preferably be the same as l circuit, and directly from the other pole of that shown in the drawing, and that the the battery through the ground or common 55 called subscribers telephone apparatus, connections and the impedance coils to the 12 answering jack line signal, etc., may be du other side of the circuit. plicates of the apparatus, jacks, and relays WVhen the subscribers have finished talkillustrated as constituting the apparatus of ing and have hung up their receivers, the the calling subscribers line circuit. The in-- opening of the line circuits takes the current 60 sertion of the calling plug in the multiple I away from the relays 28 and 31, thereby aljack connected with the called subscribers lowing the armatures 29 and 33 to close the line complete a short circuit around the l circuits of the lamps 30 and 32, it being un line relay of the called subscribers line in derstood that the energizing circuit of each the same manner that the insertion of the J supervisory relay includes the switch-hook answering plug served, as explained, to of a subscribers apparatus. The operator,

observing these two signals, understands that the subscribers have finished talking and have hung up their receivers.

From the foregoing, it will be seen that the invention contemplates a simple and highly etficient telephone system in which only two strands are necessary for the cordcircuit, and in which the system is, at the same time, characterized by all or at least most of the approved methods of operation. Other advantages will be obvious to those skilled in the art.

It will be readily understood that the resistances of the various relays, impedance coils, etc., can be varied or changed to suit the requirements of any particular case, and in such manner as to insure the desired results.

I claim as my invention 1. In a telephone system, the combination of a subscribers line, substation apparatus including a hook-switch for opening and closing the line circuit, switchboard apparatus including a spring-jack and a line relay connected with thesubscribers line and including also an operators cord-circuit provided with a plug adapted for insertion in said ack, a battery at the central station connected and arranged for supplying current to the line for both talking and signaling purposes, an impedance coil in series with said line relay between one side of the line and one pole of said battery, and a line lamp signal having a local circuit provided with a normally open switch point controlled by said line relay said local circuit including said impedance coil, and the said plug having a tip contact adapted to shortcircuit the said line relay when inserted in the jack.

2. In a telephone system, the combination of a subscribers line,.substation apparatus involving a subscribers hook switch for opening and closing the line circuit, a battery at the central station connected and arranged for supplying current to the line for both signaling and talking purposes, a

line relay and 1mpedance coil connected in series and serving as medium of connection between one side of the line and one pole of said battery, another impedance coil serving as medium of connection between the other side of the line and the other pole of the battery and a line lamp signal having a local circuit provided with a normally open switch-point controlled by said relay, said local circuit including said battery and one of said impedance coils.

3. In a telephone system, the combination of a subscribers line, substation apparatus including a subscribers hook-switch for opening and closing the line circuit, a spring jack in which said line terminates, line signal associated with said jack and adapted to be controlled by said hookswitch, a battery at the central station connected and arranged for supplying currentto the line for both talking and signaling purposes, vided with a plug adapted for insertion in said jack, a supervisory relay associated with the cord-circuit and adapted to serve as medium of connection between the tip of said plug and one pole of said battery, suitable connection between the thimble or testing ring of the ack and the other pole of said battery, and a supervisory lamp having a local circuit including the battery and contacts of said supervisory relay and including also the sleeve contacts of the plug and jack, but excluding the substation apparatus.

4. In a telephone system, the combination of a subscribers line, sub-station apparatus including a subscribers hook-switch for opening and closlng the line circuit, a battery at the central stat-ion connected and arranged for supplying current to the line for both talking and signaling purposes, a jack connected with the line and provided with three contacts, a line relay connected between two of said contacts, an impedance coil serving as medium of connection between one terminal of the said relay and one pole of said battery, another impedance coil serving as medium of connection between the other side of the line and the other pole of the battery, a line lamp signal having a local circuit controlled by said relay, said local circuit including the battery and the first-mentioned impedance coil, an operators cord-circuit provided with a plug adapted for insertion in said jack, said plug having but two contacts, the tip contact of the plug being adapted to engage two of the contacts in the jack for the purpose of shortcircuiting the line relay, a supervisory relay adapted to serve as medium of connection between one pole of the battery and the tip contact of the plug, and a supervisory lamp signal having a local circuit adapted to be controlled by said supervisory relay when the plug is in the jack, said local circuit of the supervisory lamp signal including a talking strand. of the cord-circuit and the sleeve contacts of the plug and jack.

5. In a telephone system, and in combination with the essential elements thereof, a line lamp signal having a normally open local circuit, and a battery and an impedance coil included in said circuit together with a spring jack having contacts which are excluded from said circuit and the said im pedance coil and battery being connected in series across the talking circuit.

6. In a telephone system, the combination of a line relay, means for shunting the said a suitable line relay when the operator establishes connection with the line, a line lamp signal havmg a normally open clrcuit, and a centralan operators cord-circuit proacross said line, other lines to which said battery is common in the same bridged relation, a supervisory lamp signal, a supervisory relay controlling said lamp signal and energized over the line while the latter is in use, a local circuit for said lamp signal and a plug switch having contac'tsin the said local circuit.

11. In a telephone system, a subscribers line, a line relay, a supervisory lamp signal, a single supervisory relay controlling said lamp signal, a battery for talking purposes, an impedance coil connecting one pole of the battery with one side of the line, the supervisory relay controlling said lamp signal being energized over the line while the latter is in use, and a local circuit for said lamp signal, each circuit including said impedance coil.

12. In a telephone system, the combination with line and cord circuits, of a spring jack for the line circuit having its test con tact connected wit-l1 a limb of the telephone line, a central source of current, an impedance coil connected between a pole of said source and the test contact of said jack, a supervisory signal for the cord circuit normally connected between the sleeve contact of the plug and the other pole of said source, and a supervisory relay for the cord circuit ized source of current and an impedance coil included in the circuit of said lamp, said impedance coil and relay connecting one side of the line with the source of current.

7. In a telephone exchange system, the combination of a line lamp circuit, a line relay, a talking circuit, an impedance coil connected with the talking circuit and included in said line lamp circuit, means for shunting said relay to retire the line signal, a battery for operating said relay and line signal, and a battery circuit including said relay and impedance coil in series.

8. In a telephone system, a subscribers line, a battery for talking purposes, an impedance coil permanently connecting one pole of the battery with one side of the line, a supervisory lamp signal, a supervisory re lay controlling said lamp signal and ener gized over the line while the latter is in use, and a local circuit for said lamp signal, said circuit including said impedance coil and being controlled by said relay.

9. In a telephone system, a subscribers line, a battery for talking purposes, an inr pedance coil connecting one pole of the battery with one side of the line, a supervisory relay controlling a lamp signal and energized over the line while the latter is in use, and a local circuit for said lamp signal, each circuit including said impedance coil. controlling 10. In a telephone system, a subscribers circuit of said supervisory signal. line, a battery for talking purposes, an im- Signed by me at Chicago, Cook county, pedance coil interposed between one pole of Illinois, this (3th day of March, 1903. the battery and one side of said line an im- 7 pedance coil and a relay coil connected in HENRX E series and interposed between the other pole of the battery and the other side of the line, said battery thereby permanently bridged lVitnesses:

CHAS. lV. HIcKoIi, lVM. A. HARDnRs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C.

normallyclosed contacts in the t g i 

